Major Valk Larn and nurse Calla Belan meet during the Gaantish and Enithi war. First he was her prisoner, kept sedated to frustrate his telepathy and keep him from communicating from other Gaant prisoners. Then she was his prisoner when Gaant captured Enith.

During the time she was administering his sedatives, she and another nurse played chess to pass the time. Valk was intrigued by the game, especially by the rich thoughts emitted by the players. He wanted to learn how to play, but was never clear-headed for long enough to ask Calla.

Once he was released and became an officer, Valk recognized Calla in his prison camp. He summoned her alone, something hardly ever done with the enemy, and asked her to teach him how to play chess. At first she declined. Since it was a game of strategy, he would just be able to read her mind and know her planned moves. He insisted anyway, and so she made a makeshift cardboard chess board and pieces to teach him on. He learned quickly, and they started a game but never finished. In the prison Calla became very depressed and was sent home.

Now, the two groups of people are finally at peace and the war is over. Calla gets a telegram from Valk at the military hospital asking her to visit and bring the game. He has been seriously injured, but remembered her anyway. She comes and together they recount the war through her mind while picking back up from their last chess game. Calla wins while hospital workers watch them play.